ISLAY, Scotland — On Islay, an island with a population of around 3,000, disagreements have never run deep. The last big dispute goes back more than two decades; it involved the conservation of an indigenous butterfly.

There are only two policemen here, including one traffic officer, and the approach to dealing with anything unpleasant — be it the rainy, blustery weather or an argument with neighbors — often involves a wee dram of smoky malt whisky, for which the island is famous.

But Scotland’s independence referendum is less than a week away, and tensions are brewing among the Ileachs, as the people of Islay (pronounced EYE-luh) are called.

The outcome of the vote on Thursday will probably be bitter for many — opinion on the island appears to be split roughly 50-50, said Calum Murray, the editor of the local newspaper. As a result, many residents fear that their community will be deeply and enduringly fractured.

Some residents complain, without naming names for fear of stirring the pot, that those in favor of independence have encouraged a subtle form of psychological bullying. Posters for the yes campaign and Scottish flags are conspicuous around the island. One placard in support of remaining in Britain was tacked to the wall of a farm, far from the sight of most, though well within the view of the sheep in an adjacent field.

Anthony Willis, an Englishman who runs Kilchoman, a small distillery, said the referendum had put him at odds with most of his employees, who broadly support independence. “They know my views,” he said, pursing his lips.

“If the outcome is decisive, then it will be an easier transition, and we’ll go about our ways quietly,” he said. “But if it’s a close call, it’s going to be a shame because it’s going to be hugely divisive.”

Distillery owners like Mr. Willis are worried about the impact of Scottish independence on their business, such as the potential loss of markets and uncertainty surrounding Scotland’s future currency. “I absolutely support more devolved powers to Scotland,” he said, “but to have the support of the United Kingdom is very vital.”

Another distillery owner, who requested anonymity given the tension around the issue, said half-jokingly of his staff members: “I just bloody hope they won’t burn down my house.”

Ronald Brown, 76, describes himself as a passionate Scot, but he plans to vote against independence because of the social and economic risks. “We got along so well before,” he said wistfully, while proudly showing a pair of swords in his living room that date from the 1746 Battle of Culloden, when Scottish clans from the Highlands fought alongside English pretenders to the crown. “United we stand, divided we fall,” he said.

But even those supporting independence are not naïve about the challenges facing them.

“We know we’ll have problems,” said Charlie Shaw, 72, as he drove his van at full speed on Islay’s bumpy roads, narrowly missing another car. “We expect to be worse off, but we need a chance to sort them out ourselves.” But he wants independence. “I just want my country back,” he said.

Born and raised on Islay, Mr. Shaw said he spoke Gaelic at home, though when he was growing up, schools did not teach the language or Scottish history. The introduction of the unpopular poll tax in Scotland by Margaret Thatcher’s government in 1989, a year before it was imposed in England and Wales, made Scots “feel like guinea pigs,” he said.

“We don’t need to be like beggars, asking London money for this and that,” he added.

Stevie Ewing, who works at the Laphroaig distillery, agreed. “It’s my heritage, it’s the way I was brought up,” he said, showing two tattoos, both emblems of Scotland. “I love my whisky, and I love my football club. If you want to do something, do it.”

But Stuart Doyle, who returned to his native Islay a few years ago after living for years in England, is unsure, though his wife plans to vote for independence. “Our forefathers fought the English hundreds of years ago when our language and culture were taken from us,” he said. “But that’s in the past.”

He said he would have his children in mind when voting. “I probably won’t reap the benefits, but maybe my children and theirs will,” Mr. Doyle said.

But whether the Ileachs choose the best or worst decision for themselves, Mr. Shaw said, “whatever the outcome, nothing is the same anymore.”

A version of this article appears in print on , on Page A4 of the New York edition with the headline: Where a Sip of Whisky Usually Cures All, a Secession Vote Proves Bitter. Order Reprints | Today’s Paper | Subscribe